JP2005525281A - Panel element with heating layer - Google Patents

Abstract

A panel element with a toughened pane, provided with a total surface coating, which is electrically conducting and heated by applying an electrical voltage by electrodes. A partial zone of the coating is electrically separated by a separating line. Specifically, an inner surface zone of the coating is separated electrically, by at least one peripheral separating line, from an external edge region of the coating, and the electrodes are placed inside the surface zone surrounded by the peripheral separating line.

Description

  The present invention relates to a panel element comprising a tempered glass plate having a full surface coating, the coating being electrically conductive and heated by applying a voltage by means of an electrode, wherein a part of the coating is electrically separated by a dividing line. ing. This type of heat coating applied to glass usually serves to remove condensation and ice from a glass plate used as a transparent glass plate, so that people can easily see it.

  The basic features are disclosed in DE 40115541 in the form of a tempered glass plate with warning and electric heating. Using a dividing line drawn by the laser beam, a portion of the conductive heating coating of this glass plate is electrically isolated from the main surface area of the coating. A partial area is used as a sensor to detect breakage of the tempered glass plate in question. The tempered glass plate can be incorporated into a laminated glass plate or an insulating glass mounting element. Preferably, a system of layers is used that can withstand high heat loads and can be deposited on the surface of the glass plate sufficiently before the glass plate is strengthened.

  German Offenlegungsschrift 3 644 297 presents several examples of dividing the heating coating on the windshield of a vehicle. Thus, segmentation can be performed by unsurfaced areas and / or cuts made mechanically or by a laser beam. These divisions must establish a current flow in the coated surface and work to pass it in an appropriate manner, ensuring as uniform a current density as possible in the plane of interest.

  The operation of these heating layers requires a relatively high voltage. In particular, it is necessary to provide a reliable electrical insulation at the edge of the glass plate in question, which can be coated over the entire surface.

  In another panel element (German Patent DE-B-211376), the conductive heat coating does not extend to the edge of the panel, so that a spacer frame (cadre d ') for the insulating glass vitrage unit. The adhesive can be adhesively bonded directly to the (uncoated) edge region of the glass plate without special care. A conductor supplying electricity to the electrode is guided through the hole and sealed within the spacer frame.

  In various ways, it is known that other regions can create uncoated regions on a fully coated substrate. By placing the mask during the coating operation, the substrate can remain free from the beginning within the coated area. In order to remove the coating on a partial area of the substrate, the coating can be removed again by mechanical polishing, chemical means, or for example by a laser beam.

  In the panel element known from EP-A-09898781A2, together with the solution proposed by German utility model No. 29923417U1, the coating extending to the edge of the glass plate is at least on the spacer frame It is masked by an insulating layer covering it so that there is no conductive coupling. Further, the spacer frame may be made of a material having a high electric resistance, for example, plastic. Similarly, an adhesive with a high electrical resistance can optionally be used. In these models, the conductor supplying the electrodes is routed between the coated surface of the glass plate and the spacer frame or through a hole in the spacer frame.

  German Offenlegungsschrift 19644044 describes a laminated glass sheet for motor vehicles, the laminate comprising a polymer film with a thermally insulating conductive coating, which coating is sensitive to corrosion. The narrow edge strip of the coating on the thin film is separated from the main surface area of the coating by the dividing line to prevent the corrosion effect starting from the edge of the thin film from propagating to the glass plate field of view. The parting line is cut by the laser beam so that it is not visually visible in the coating. The laser beam is adjusted to be absorbed only by the material of the coating and to break the coating only in areas that are locally confined by the emitted heat while leaving the support film itself intact.

  It is an object of the present invention to provide a panel element that is not only suitable as an independent heating panel element that is further improved with a heating layer and does not have the function of a pane.

  According to the invention, the object is that the inner surface area of the heating coating is electrically separated from the outer edge area of the coating by at least one circumferential dividing line, and the electrode is arranged inside the surface area surrounded by the dividing line. Is achieved in that it is The features of the dependent claims propose advantageous refinements for this purpose.

  When using at least one circumferential dividing line to divide the actual heating zone of the coating edge region, reliable electrical insulation at the edge of the panel element is first provided. When operating at a relatively high voltage, two or more parallel circumferential dividing lines can be provided. Basically, this allows such heating panel elements to operate at their domestic network voltage (eg 110V or 230V).

  Of course, in a manner known per se, several current paths are provided on the panel elements according to the invention, in some cases, so that the heating power can be connected or disconnected stepwise as required. Can be connected to each other separately.

  The length and width of one or more current paths, together with the surface conductivity (in ohms per unit surface area) of the layer system used, determines the power absorbed and the heating power factor of the panel elements. . Depending on the available or predetermined supply voltage, the different heating powers can be adjusted within wide limits by designing the current path, for which the maximum allowable temperature is also determined by the finished panel element. It depends on the area of use. For example, if direct contact by the user is not possible or permitted, the temperature will be well above 50 degrees. However, it is of course necessary that the adhesive layer that adheres to the glass plate to be coated, for example the adhesive film of the laminated window, is not damaged by the temperatures reached during normal operation.

  Such a panel element can be fitted or incorporated into a wall in or on the building instead of a normal heating element. For this purpose, the panel element does not necessarily have to be made in the form of a window, but may be made in the form of a mirror, a decorative surface or the like. If necessary, such panel elements can also be used to generate heat, usually in technical equipment, for example household appliances, in which case a low overall height and smoothness that is very easy to clean. The surface can have great advantages.

  Even when applying the panel element as a flat heating element without window function, the current flow does not necessarily have to be evenly distributed throughout, but at least almost prevents local overheating and damage to the heated coating. It is advantageous to adjust the current flow in this way. Layer systems deposited by the latest methods can rely on a very uniform thickness over the entire layer, but conversely can hardly produce a deliberately different coating thickness, and therefore the predetermined substrate The surface resistance over the region is different.

  When manufacturing heating panel elements without window function, an anti-reflective treatment may be dispensed with if necessary on the actual conductive layer, for example made of silver or another conductive metal. The current supply can be simplified (ordinary dielectric non-reflective layers are either non-conductive or very low conductivity), while on the other hand it is possible to obtain a decorative surface effect . However, it is left to the understanding of those skilled in the art responsible for calibrating the desired heating power to accurately determine the appropriate material for the heating layer system.

  In addition, one or more temperature sensors may be provided to detect the actual temperature of the panel element. Such a temperature sensor may be in the form of a current limiter (eg, a thermistor whose electrical / ohmic resistance increases as temperature rises). As a variant, if the panel element is likely to overheat, a separate switching component can be provided to cut off the heating current and can be controlled by a temperature sensor.

  Similar to the prior art in this field, as a variant of the panel element according to the invention, a separate peripheral area alerts if it is separated in a position and a standby current electrode is provided on each side of the dividing line. It may be in the form of a breakage detector that emits. Such standby current circuits can operate at low power or voltage so that no harm occurs.

  Other details and advantages of the object of the invention are given by the drawings of the exemplary embodiments and the following detailed description.

  The drawing is simplified.

  According to FIG. 1, the panel element 1 comprises a tempered glass plate 2 whose first main surface, in this case the upper surface, is completely covered with a conductive coating 3. The coating 3 may be optically transparent but need not be so. Preferably, the coating consists of a layer system that withstands high heat loads and comprises at least one metal layer applied prior to strengthening the glass sheet 2.

  Along the edge of the glass plate 2, two thin dividing lines 4 are made in the coating, drawn a short distance from this edge, i.e. 1-2 cm, parallel to each other and around the circumference. The circumferential outer edge strip 5 thus formed is electrically isolated from the larger remaining part of the coated surface. Thereby, edge insulation is formed in the panel element 1.

  Starting from two circumferential dividing lines 4, another pair of parallel dividing lines 6 extends for a certain length into the surface of the coating 3 at an angle. On each side of these dividing lines 6, strip-shaped electrodes 7 that are electrically connected to the coating 3 each time are provided. The cable 8 can be used to connect the two electrodes 7 by applying a voltage.

  In order to determine a defined path for the heating current through the surface of the coating 3, another dividing line 9 is provided in a manner known per se. A dividing line 9 which is generally U-shaped is directly connected to the two dividing lines 6, and the two U-shaped arms are parallel to the dividing line 6 and the two lateral sides of the panel element 1. It is. A straight dividing line 10 extends from the dividing line 4 to the two U-shaped arms of the dividing line 9. At the free ends of the dividing lines 9 or 10 on the surface, recesses 11 are provided in the surface of the coating which must avoid excessive current density in the region of these ends. The dividing lines 9 and 10, like the circumferential dividing line 4, form a high electrical resistance insulation in the coating and no current can pass therethrough.

  Overall, this results in a current path that uses the entire surface of the coating 3 that is relatively long and relatively narrow and that is surrounded by the circumferential dividing line 4. In order to establish as uniform a current density as possible during the transition between the coating 3 and the electrode 7, the electrode 7 has a length approximately equal to the width of the current path at this position.

  Only one exemplary embodiment from several feasible and usable designs for the dividing line defining the current path is shown here. For example, a laser can also be used to draw a curved parting line in the coating, for example by a robot, without great additional costs. Other examples can be inferred from the prior art discussed at the beginning.

  The embodiment of the panel element 1 according to FIG. 2 is distinguished from the first embodiment mainly by the deformation arrangement of the two electrodes and the path of the current flow. Here, the two electrodes 7 are arranged close to the dividing line 4 in parallel with one of the side portions of the glass plate 2. Such an arrangement of the electrodes 7 close to one side of the glass plate is not as visible as in the embodiment shown in FIG. The current path between the electrodes has a sinusoidal path determined by the dividing line 10. The deflection area is further provided with a curved dividing line or guide line 12 that is redesigned to avoid current peaks at the free ends of the straight dividing line 10. Of course, such a guide line 12 can also be used in the embodiment of FIG. Furthermore, several parallel guide lines may be provided. The optimum design for each of these current guide lines and dividing lines 9 and 10 must be determined individually by testing.

  A panel element of the type shown in FIGS. 1 and 2 is suitable, for example, for fitting into an insulating glass mounting unit, in which the associated spacer frame has to be simply adhesively bonded to the edge region 5. Thereafter, the cable 8 is made in a manner known per se in the form of a flat cable or printed film with a conducting part leading to the outside, and the edge between the spacer frame and the surface of the glass plate and thus in the adhesive bonding plane There is no electrical contact with the subregion. The second glass plate of the insulating glass mounting unit forms a rear mask for coating.

  Similarly, such a panel element can be suspended directly in front of the wall surface, or incorporated in it, without prior provision of a rear coating, in which case it is ensured that there is no harm from electrical operating voltages.

  In another variant, shown schematically in FIG. 3, the glass plate 2 of FIG. 1 is incorporated into a laminated glass plate, and its second rigid glass or plastic plate 13 is bonded to the adhesive sheet or layer 14 in the usual manner. Thus, the tempered glass plate 2 is assembled flat. In the cross section through the coating 3, the arrangement of two parting lines 6 between the electrodes 7 is seen, the electrodes being directly attached to the coating 3. As a variation on this arrangement, the electrode may be placed under the coating, i.e. before applying the coating on the surface of the glass plate. The electrodes may be made in the form of thin metal films or strips that are fired (when strengthening the glass plate 2) from a conductive screen printing paste. Suitable electrode embodiments, which can also be called current collector rails, have been described many times in the prior art.

  The second glass plate 13 and the adhesive layer 14 have small recesses or small holes 15 in the area of the electrodes. The recess serves to cause electrical contact with the electrode 7. Two contact conductors 16 are secured to the electrode by soldered ends 17 and soldering points 18. The contact plug of the contact conductor 16 is inside the recess 15 and can be engaged with a suitable connection plug (not shown), so that it must of course be adequately mechanically protected against dropping.

  Such an embodiment of the electrical contact of the heating layer to the outside is particularly well suited for using the panel element as a heating plate without window function. Naturally, in the embodiment according to FIG. 3, as in FIGS. 1 and 2, the paired electrodes 7 can be connected to a permanent cable, which is connected to a current source by means of a plug at the free end. Can do.

  The electrode 7 itself is opaque but can be viewed through the uncoated side of the glass plate 2 if desired. The electrode can then form a decorative element, for example a company or manufacturer logo as a variation on the simple strip shape shown in the drawing. In addition, several color effects are also obtained by coloring conductive screen printing pastes that are preferably used to manufacture electrodes.

  Of course, the area of electrical contact can be masked from vision, if necessary, by suitable means, for example by applying or overprinting an opaque decorative pattern, or by using a very dark glass component on the tempered glass plate 2. It can also be made. As a rule, the glass plate forms the surface of the panel element that is directed towards the space to be heated. In exchange of any masking, here a non-conductive opaque coating 19 is provided between the coated surface of the glass plate 2 and the heating coating 3 in the region of the electrodes and contact conductors, which coating is made of glass. Already printed on the surface and fired during strengthening before the coating 3 is applied. As a typical variant, for example, by printing two strips of conductive screen printing paste and then depositing the conductive coating 3 on the opaque coating 19 and the electrode 7 as already shown, 2 The book electrode 7 can be applied directly to the opaque coating 9. This in particular has the advantage that after applying the mechanically brittle coating 3, no new material has to be applied to the coated surface again. Furthermore, sufficient adhesion of the electrode 7 to the glass surface is ensured.

  For transport, the recess 15 is closed with a sealed durable elastic stopper (not shown), which optionally allows the plug to be placed and removed, while moisture and dust are present in the electrode 7 and coating 3. To prevent spread.

  In the representative example according to FIG. 3, one of the contact conductors 16 is combined with a temperature sensor, eg self-detecting locally the actual temperature of the panel element or coating and optionally limiting the absorbed power to harmless values. It would be possible to combine with a temperature regulating resistor. Such a temperature sensor can advantageously be integrated into one soldering end 17 of the contact conductor 16, as indicated by the chain line 20 at the end of the right contact conductor 16, so that the current of the heating current circuit is Can be placed directly in the stream.

FIG. 3 is a perspective view of a panel element with a thermal coating divided by a parting line. FIG. 6 is a similar perspective view of a variation of the panel element. FIG. 2 is a cross-sectional view through an electrical contact region of one embodiment where the panel element of FIG. 1 is part of a laminated glass plate.

Claims (21)

  In a panel element comprising a tempered glass plate (2), this glass plate comprises a conductive whole surface coating (3) heated by applying a voltage by means of an electrode (7), with a partial area of the coating being separated by a dividing line An electrically separated panel element, wherein the inner surface area of the coating (3) is electrically separated from the outer edge region (5) of the coating (3) by at least one circumferential dividing line (4); Panel element (1), characterized in that the electrode (7) is arranged in a surface area surrounded by a dividing line (4).   2. Panel element according to claim 1, characterized in that two or more parallel circumferential dividing lines (4) are provided.   A current flow is passed each time between the two electrodes (7) along a predetermined path obtained by locally insulating the coating in the surface area surrounded by the dividing line (4). The panel element according to claim 1, wherein:   The electrical resistance of the heating coating (3) is adjusted to operate at the voltage of this domestic electrical network so that the predetermined temperature is not exceeded when applying the voltage of the domestic electrical network to the two electrodes (7). The panel element according to claim 1, wherein the panel element is characterized by the following.   5. The coating according to claim 1, wherein the coating is formed by a system of layers that withstands high heat loads and is deposited on the surface of the glass plate before strengthening. Panel element according to paragraph.   Panel element according to any one of the preceding claims, characterized in that the connection of the electrode (7) is led from the coated glass plate (2) without contact with the edge region (5). .   7. A panel element according to any one of the preceding claims, characterized in that the electrode connection is directed outwardly on the edge region and thereby electrically insulated from the edge region. .   Panel element according to any one of the preceding claims, characterized in that another plate (13) is laminated on the coated side of the glass plate (2).   9. A panel element according to any one of the preceding claims, characterized in that the spacer frame for the insulating glass mounting unit is adhesively bonded to the separated edge region (5) of the coating.   9. At least one recess (15) is provided in another plate (13) assembled to the coated glass plate (2) to cause an electrical connection to the electrode (7). The panel element according to any one of 9 and 9.   11. Panel element according to claim 10, characterized in that a plug connection (17) for the electrode (7) is arranged in the recess (15).   12. A panel element according to any one of the preceding claims, characterized by a temperature sensor for detecting the actual temperature of the heated coating.   13. A panel element according to claim 12, characterized in that the switching element is controlled by a temperature sensor to cut or reduce the heating current if a predetermined temperature threshold is exceeded.   14. The separated edge region (5) of the coating (3) is separated by at least one dividing line and used as a current path according to claim 1. Panel element.   15. The panel element according to claim 1, wherein at least a region of the electrode (7) is hidden from view by a mask.   16. Panel element according to claim 15, characterized in that visual masking is obtained by using an opaque glass component in the tempered glass plate (2).   Panel element according to claim 15 or 16, characterized in that the visual masking is made by an opaque decorative element (19).   18. Panel element according to claim 17, characterized in that the opaque decorative element (19) is arranged flat between the surface of the glass plate (2) and the heat coating (3).   19. The electrode (7) according to any one of the preceding claims, characterized in that the electrode (7) is made by applying and baking a conductive screen printing paste before or after applying the heat coating (3). The described panel element.   20. A panel element according to claim 19, characterized in that the electrodes form a visible decorative element.   21. Panel element according to claim 19 or 20, characterized in that a plug connection (16) for engaging an electrical connection conductor is connected to the electrode (7).

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